Here is my trigger mod for the qb78 which could be used for other air guns with relativity wider sears (read not 22xx). First the trigger as it sits in its housing.
Next you open up the trigger housing and polish all the contact points on the round sear (the one that engages the hammer). Bring it up to a mirror shine, my dremel made quick work of this working right up to the little blue polishing stone and then the felt one and some metal polish.
After you're done with that. You take the other trigger out and angle the contact point that engages the sear to a knife edge, polish it to a mirror shine and you're done. What this does is gives a lower amount of surface friction. Add to that some molly lube on all contact points (including the pins that hold the parts in place) and you will have a trigger that is as smooth if not smoother then butter.
